It is known in the art to which this invention pertains that sight glasses are employed in connection with certain components of refrigeration systems in order to obtain visual access to the interior thereof. Receivers are illustrative of such refrigeration components, and one prior art method of securing the sight glass body to the refrigeration component or vessel was to effect a threaded connection therebetween. Leakage of refrigerant from between the pipe threads was the inevitable result. In substitution for the threaded connection, an expedient employed by those skilled in the art has been to effect securement of the steel sight glass mounting body to the steel refrigerant component utilizing either resistance welding or arc welding techniques. Satisfactory results were again not obtained. First, during welding the steel surfaces often reach temperatures of approximately 3000.degree. F., and by heat conduction, damage to the sight glass itself often occurs. Second, by reason of the effective weld bond between the two steel bodies, it is essentially impossible to remove the sight glass body if replacement of the sight glass portion is required.